The overall hypothesis is that the decline in physical activity habits and resultant increase in body fat reduces exercise capacity and muscle mass in older women. These lifestyle changes worsen metabolic and cardiovascular risk factors. Therefore, continued involvement in exercise training programs which increases or preserves fat-free mass will prevent functional declines in older women. Although exercise is frequently recommended to enhance overall fitness, it is unclear as to whether endurance or resistance exercise is more effective in attenuating functional and cardiovascular declines in women. We will systematically compare the effects of endurance and resistance exercise on physical activity, cardiovascular fitness, insulin sensitivity, and fat metabolism in older women. The results of this study will lay the groundwork for appropriate exercise prescriptions to reduce cardiovascular and metabolic risk and enhance physical function in older women. During 1997 we screened five, and enrolled into the training program three volunteers. In 1998 we plan to screen 25 to 30 volunteers.